1. Field of the Invention
The present invention relates to a bipyridine derivative functioning as an important intermediate in the fields of for example pharmaceutical products, agricultural chemicals, catalyst ligands, combinatorial chemistry, organic electroluminescence devices, electron charge transfer substances, electrophotograpic photosensitive substances and dyes.
2. Description of the Related Art
Use of bipyridine derivatives mainly including 2,4′-bipyridine is developed for a wide variety of fields. The derivatives draw attention as very attractive compounds. In the fields of recent pharmaceutical and agricultural chemicals, for example, the derivatives are used as α1A-selective antagonists (Canadian Journal of Chemistry, 2002, Vol. 80, No. 6, pp. 646-652).
In the field of ligands, additionally, numerous reports have been issued including a report about the use thereof as a ligand for ruthenium metal (Canadian Journal of Chemistry, 2002, Vol. 80, No. 6, pp. 646-652), as ligands for copper and cadmium (Journal of Organometallic Chemistry, 2002, Vol. 655, pp. 31-38) and as a ligand for manganese (II), cobalt (II), nickel (II) or copper (II) (Polish Journal of Chemistry, 2002, Vol. 76, No. 7, pp. 1047-1052).
As organoelectroluminescence devices, for example, there are organoelectroluminescent materials using highly luminescent organic iridium complexes and an example of the use thereof for organoelectroluminescence devices (Official gazette of JP-A-2003-147345).
In the photosensitive field, the use thereof for the purpose of providing a silver halide photosensitive material with high sensitivity, improved storability of fresh samples and less contamination of dyes is reported (Official gazette of JP-A-2001-152044).
As dye enhancers, a report tells about a photoelectrochemical battery of dye enhancement type and with less electricity generation loss as well as the usefulness of a bipyridine-carboxylic acid-ruthenium (II) complex hydrate as a dye enhancer for photoelectrochemical battery of dye enhancement type and with smaller inner resistance (Official gazette of JP-A-2003-163037).
In a wide variety of fields, additionally, as many as 200 patents and references report the assessment of their usefulness (Journal of Thermal Analysis and Calorimetry, 2000, Vol. 60, No. 1, pp. 145-150).